JP3371646B2 - Dry etching method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] [0001] The present invention relates to a semiconductor device.
Precision using plasma equipment used for fine processing such as fabrication
Dry etching that etches wiring materials and insulating films
Related to the logging method. [0002] 2. Description of the Related Art As semiconductor devices become more highly integrated,
Minimum design rule is significantly reduced, 256M
Large-capacity memory devices such as DRAM and 64MSRAM
Requires fine processing technology of 0.25μm class
You. Dry etching, one of the main technologies
Technical requirements are also becoming increasingly sophisticated.
You. The technical requirements include etching masks and underlying materials.
High selectivity to the material layer, good shape controllability,
Cutting speed, low damage, low contamination, good uniformity
And good reproducibility. For example, a three-dimensional structure of a multilayer wiring or a device structure
Of a given material film on a substrate with an increased surface step
When performing dry etching, etch the side wall surface of the step.
In order to prevent the residue of stringing (stringers),
Sufficient over-etching is required. At this time,
Erosion of the underlying material film due to etching during
Desired pattern shape such as Ducat or inverted taper shape
Deterioration must not occur. In other words, extremely high background selection
Properties, mask selectivity, and anisotropy are required. [0004] In addition to the above-mentioned high step machining,
Also, for example, processing of the gate electrode of a MOS transistor
Some processes are extremely difficult. This is the gate electrode
Is usually the minimum feature size for a given design rule
Is the electrode pattern to which the
For fluctuation of channel length and success or failure of LDD sidewall formation
Influence directly, only a few 10nm thick
High under 50 selectivity for gate insulating film
Must be maintained, especially as a constituent material of the gate electrode.
When a high melting point metal polycide film is used,
Because it is a laminate of two types of films with different etching characteristics
Difficult to set conditions for anisotropic processing, etc.
It depends on the circumstances. [0005] By the way, a plasma for dry etching is used.
Various types of devices are known as device devices.
One of them is the triode type plasma shown in FIG.
There is an etching device. [0006] This device forms a ceiling portion of a chamber 41.
Upper electrode 42 and a part of the side wall surface of the chamber 41
A high-frequency electric field between the annular side wall electrode 44 and
To generate plasma P, and use this plasma P
In this way, dry etching of the wafer W is performed. the above
The chamber 41 is provided with a drain provided on the back side of the upper electrode 42.
High vacuum evacuation in the direction of arrow A through the air hood 43
The arrow B through the gas supply pipe 44₁, B₂From the direction
These baluns are supplied with a predetermined etching gas supply.
The inside of the container is maintained at a predetermined pressure by a pressure switch. The side wall electrode 44 has a matching network.
RF power supply 50 for plasma excitation is connected via
Has been continued. The surface of the side wall electrode 44 is usually made of quartz.
Covered with an RF electrode cover 45. In general,
Ground on the surface of the electrode (RF electrode) connected to the RF power supply
Larger ion sheath forms at the surface of the electrode
The ions accelerated by the DC electric field
Sputter the extreme surface. In the case of the above device, the side wall electrode 4
4 is in direct contact with the plasma
The risk of particle and metal contamination.
Good. The RF electrode cover 45 avoids such contamination.
Provided for protecting the surface of the side wall electrode 44.
Have been. A member for holding the wafer W in the chamber 41
Is a conductive wafer forming the bottom surface of the chamber 41
-Stage 47. This wafer stage 47
Instead of a counter electrode to the upper electrode 42, plasma
An electrode for applying a substrate bias independently of generation.
You. This substrate bias is applied to the RF power source for plasma excitation.
RF power supply 52 for bias application having a frequency lower than 50
Wafer stay via matching network 51
It is applied by connecting to the die 47. The wafer W is placed on the wafer stage 47
It is fixed using a pump 48. Etch if necessary
The focus ring 55 for defining the
Used. Note that these clamps 48 and focus
Wafer peripheral members such as ring 55 also have ion-sputtering action.
Because it is strongly received, it is covered with a quartz cover to prevent contamination.
Have been. On the outer peripheral side of the chamber 41, a plurality of permanent
Magnets 46 are arranged in a predetermined arrangement, and inside the chamber 41
A multi-cusp magnetic field is formed in the section.
Another permanent magnet 5 is also provided on the back side of the upper ground electrode 42.
3 are provided. From such a configuration, this etcher
Is a magnetic confinement reactor (MCR = Magnetic Confi
nement Reactor).
High plasma density can be obtained by confining to pact
You. In this device, the side wall electrode 44 is made of quartz.
Because it is covered with the RF electrode cover 45
While the mask P is being excited, the RF electrode cover 45
Due to the interaction with the plasma P, the RF electrode cover 45
Oxygen-based active species are released from the surface. This oxygen-based active species
Can be used for the etching reaction,
In the dry etching involved, the etching gas
Especially during the₂Equivalent to the case without adding
The effect of can be obtained. Here, dry etching involving oxygen
Is a gate electrode processing. Configuration of gate electrode
Use of tungsten (W) -polycide film as material
With the generalization, HBr /
O₂, Cl₂/ O₂, HBr / Cl₂/ O₂Etc. in recent years
It has become mainstream. O₂Is added,
O inside^*(Oxygen radicals) in the WSix film
Of W in the form of oxychloride (WClxOy)
This is to speed up the etching. this
Is a tungsten oxychloride (typically WCl₄O)
Has a boiling point of tungsten chloride (typically WCl₆, WC
l₅) Is considerably lower than the boiling point.
Further O₂Indicates that a strong SiOx-based
Form a side wall protective film to minimize ion incident energy
Energy and excellent anisotropic shape.
You. [0013] Such dry etching is performed as described above.
If it is performed using a chucking device, it plays an important role in the etching reaction.
Oxygen-based active species that perform
Will be able to pay. Moreover, its supply stability is
Better than system supply. [0014] As described above, the chamber
The unique feature of oxygen supply from 41 internal components
With a triode type plasma etching device with color
Yes, but may cause problems depending on the type of etching
There is also. One of the problems is the use of hard masks.
Of the anisotropic shape of the etching pattern
The first is that it cannot handle etching of SiOx films.
You. These problems will be described sequentially. A hard mask is an inorganic material such as SiOx
Etching mask composed of
For general masks formed using organic resist materials
The advantage of less risk of carbon contamination
Having. For example, in recent years, self-alignment has been
In the contact process,
Offset SiOx film is hard
Play the role of a This hard mask itself is
By etching SiOx film through dist mask
Formed, but then the resist mask is removed and
Uses the above SiOx film pattern as a hard mask
I have. Here, dry etching of the W-polycide film
Through a hard mask and Cl₂/ O₂mixture
When using gas, the lower polysilicon film becomes anisotropic
Even if it is processed, the WSix film on the upper layer side
Dust is likely to occur. This occurs in this system
O^*Is optimal for the polysilicon film
Is too much for the WSix film. Resist
・ If a mask is used, C (charcoal) supplied from here
Element)^*Was able to capture and consume
This consumption effect cannot be expected when using a mask.
O^*Is likely to be excessive. But
As described above, O determined by the device configuration^*Amount generated
Cannot be suppressed below a certain value. Further, the above-mentioned etching apparatus uses SiOx
Cannot be used as a film etcher. This is the side
An RF electrode cover 45 made of quartz covering the wall electrode 44 is the same.
This is because it is sometimes etched. Therefore,
Triode type used as SiOx film etcher
In the plasma etching apparatus, the RF electrode cover 45
Instead of quartz, alumite (aluminum oxide) or aluminum
Consists of mineral ceramics. Here, recent semiconductor processes include:
For example, like bit line contact processing for DRAM,
Penetrate through the laminated film of SiOx film / polysilicon film / SiOx film
Through the dry hole to open the contact hole
Ching may be performed. At this time, as described above
In addition, both the SiOx film and the polysilicon film are
I can't etch with an etching machine
Conventionally, SiOx film etcher and polysilicon film etcher
Etch while transferring wafer W between two devices of char
Was going on. But one contact hole
Since the device is switched twice in the middle of opening the
Through holes compared to normal contact hole openings
Put has fallen by nearly one-third, causing a major hindrance to productivity
Have come. As described above, the conventional triode type
For plasma etching equipment, O^*Controllability of supply,
Of the etching target due to the difference in
There is room for improvement with respect to restrictions. Therefore, the present invention
Aims to make this improvement. [0020] SUMMARY OF THE INVENTION The present invention is directed to the above-mentioned object.
It is suggested to reach. The basic idea
Is a triode type plasma etching system.
Near the side wall electrode
Do not release oxygen-based species by plasma contact
(Hereinafter referred to as “does not release oxygen”) First member
And release oxygen-based species (hereinafter “oxygen release possible”
Describe. ) A second member, and each of the two members
Etching by changing the relative ratio of Zuma contact area
O in the reaction system^*Is to freely control the total amount of Here, the constituent materials of the first member and the second member are
And practically useful materials are aluminum oxide
Materials and SiOx-based materials. The relative ratio is determined by the first member and the second member.
Components and concentric with respect to the axis of the chamber and close to each other.
The first member and the second part by the control means;
Can be changed by changing the relative position of the material
You. This change in the relative positional relationship is performed along the axial direction of the chamber.
Up and down, or rotate around this axis.
It is a stool. If such a plasma is used in the apparatus, mechanical
O in the chamber by simple operation^*Easily control the amount of
It is possible to etch polysilicon film, SiOx
Film etching, etching using a hard mask,
Etching of a laminated film of a silicon film and an oxide film
One etching system can handle various processes
Become like [0024] DETAILED DESCRIPTION OF THE INVENTION In the present invention, a shaft
A first member (oxygen release
No contact) and each plasma contact area of the second member (oxygen release possible)
To change the relative ratio of (a), the first member is fixed
The material and the second member are movable members. (B) The first member is movable.
(C) the first member and the second member
Both of the two members are movable members.
Then place both members in the chamber and move the movable members
It is driven using a moving mechanism. Whichever configuration you choose,
However, O in the chamber^*That affect the total amount of
Is the absolute plasma contact surface of the second member (can release oxygen)
It is a product. However, the first member (without releasing oxygen)^*
That chemical species that can consume
It is a premise. Therefore, the plasma contact area of both members
Optimizing the relative ratio means that the O^*of
The total amount will be optimized. As the first member,
At least its plasma contact surface is made of aluminum oxide
And the second member
The plasma contact surface is made of SiOx-based material
It is preferable to use one that is used. It is considered that the fixing member is most practical.
The member is the side wall of the chamber. Chamber side wall
The largest ion source in the area covering the wall electrode
Because of the putter effect, at least the first part
It is a special feature of the present invention that the material or the second member is provided.
It is effective for The first member or the second member has a side wall itself.
May be composed of a thin film on the side wall surface.
It can be applied by forming technology or
Paste these appropriate solid members (blocks, tiles, etc.)
It can also be arranged by a method such as shaking. Note that this
The first member and the second member do not always have a chamber on the side wall surface.
Is not continuously covered along the circumferential or axial direction of the
May be. One of the movable members is paired in proximity to the side wall.
It can be a plate-like member that can be oriented in the direction. This plate
If the material is a ring-shaped member with no opening,
To raise and lower along the axial direction of the chamber using a structure
The relative ratio of the plasma contact area of the first member and the second member
Can be changed. In particular, the second member (oxygen
Can be released discontinuously on the side wall of the chamber,
Slit, window, etc. made of the first member (without releasing oxygen)
Using a ring with an opening and using a drive mechanism
By rotating it about the axis of the chamber.
The degree of exposure of the second member through the mouth, ie the plasma
The contact area can be changed. Or the same opening
Double the ring with the inner ring and outer ring
The width of the opening may be controlled by the difference between the rotation angles. This double
According to the ring configuration, the arrangement of the second member that releases oxygen is
It may be continuous along the circumferential direction. Both the first member and the second member are movable members.
The first member and the second member alternately along the circumferential direction.
Composed of an outer ring as shown in FIG.
The inner ring with opening is concentrically arranged close to the inner ring.
Plasma contact area of the second member through the opening by rotation
Should be changed. Here, the configuration of the outer ring
Is discontinuous on the inner wall surface of the ring-shaped member composed of the first member.
Even if the second member is arranged on the second member,
The first member is disposed discontinuously on the inner wall surface of the ring-shaped member.
May be used. If possible, the first member
And the second member are alternately joined to form an outer ring as a whole.
It does not matter even if it constitutes a tag. In the plasma apparatus of the present invention, the desired
Plasma contact surface of first member and second member according to process
The relative ratio of the products can be set optimally. For example,
O to use a hard mask^*Is likely to be excessive
In the etching, the plasma contact of the second member (can release oxygen)
It is only necessary to perform a mechanical operation to reduce the area.
O to achieve anisotropy^*Wants to generate extra etching
Then, it is necessary to increase the plasma contact area of the second member.
What is necessary is just to perform a mechanical operation. Depending on the setting of such relative ratio
And one plasma device is, for example, an SiOx film etcher.
-Can be used as a polysilicon film etcher
Becomes Moreover, if this setting is changed continuously,
That is, during the etching, the first
By driving one member and / or the second member, the substrate
It consists of insulating film and wiring film in the same chamber
Performing multilayer film etching as a continuous integrated process
Becomes possible. As a result, semiconductor device manufacturing
Significant improvements in puts and costs. [0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, prior to the description of an embodiment to which the present invention is applied,
Thus, a technique prior to the present invention will be described. Prior Example 1 Here, the fixing member is made of alumina ceramics (oxygen release
The movable member is a synthetic stone.
Elevating side wall protection ring made of UK (can release oxygen)
One configuration example of triode type plasma etching equipment
This will be described with reference to FIGS. This etching apparatus uses a ceiling of the chamber 1
Of the upper ground electrode 2 constituting the portion and the side wall surface of the chamber 1
High frequency electric field between the annular side wall electrode 5 constituting a part thereof
To generate plasma P, and use this plasma P
Then, dry etching of the wafer W is performed. Up
The side wall surface of the chamber 1 is made of alumina ceramics.
You. The inside of the chamber 1 is on the back of the upper ground electrode 2.
Through the exhaust hood 3 provided on the side
While the air is exhausted, the arrow B through the gas supply pipe 4₁,
B₂A predetermined etching gas is supplied from
These balances keep the inside at a certain pressure.
ing. The side wall electrode 5 has a matching net
An RF power source 10 for plasma excitation is connected via a work 9.
Have been. Here, the frequency of the RF power source 10 for plasma excitation is
The wave number was 13.56 MHz. The member holding the wafer W is the above chamber
1 is a conductive wafer stage 7 constituting the bottom surface
However, the wafer stage 7 is opposed to the upper ground electrode 2 described above.
Substrate electrode independently of plasma generation.
This is an electrode for applying bias. This substrate bias
Are lower in frequency than the RF power source 10 for plasma excitation.
Matching RF power supply 11 for matching network
Connecting to the wafer stage 7 through the
Is applied. This bias application RF power supply 12
The frequency is selected in the range of about 100-500kHz
can do. The outer peripheral side of the chamber 1 has a plurality of
It is circulated by the permanent magnet 6. This permanent magnet 6
Either the S pole or the N pole faces the wall of
The magnets in contact with each other are arranged so that their polarities are opposite to each other.
As a result, a multi-cusp magnetic field is formed in the chamber 1.
To achieve. Also, a permanent magnet 1 is provided on the back side of the upper ground electrode 2.
7 are provided. In addition to such a configuration, in this prior example,
As a husband, a vertically movable side wall protection ring 14 made of synthetic quartz
Was arranged. The liftable side wall protection ring 14 is
The lower end of the ring is supported
Connected to the actuator 16 via the holding member 15.
You. This actuator 16 is manually controlled by an operator.
Control signal by computer control or automatic control by computer.
Control the amount of movement in the direction of arrow B by transferring the signal
Is done. FIG. 2 shows the side wall of the chamber 1 and the liftable side wall holder.
FIG. 4 is a diagram showing the positional relationship of the protective ring 14 in a more easily understood manner.
You. According to this structure, the liftable sidewall protective phosphorus is used.
Plasma on the side wall surface of the chamber 1 according to the amount of elevation of the
As the contact area changes, the elevating side wall protection ring 1
The plasma contact area of No. 4 also changes. Here, FIG.
Raises the elevating sidewall protection ring 14 to the highest level
Then, the plasma P is substantially lifted and lowered by the side wall protection ring 14.
And the synthetic quartz is ion-sputtered.
O 2 in the etching reaction system^*Supply is expected
Become so. In this state, oxygen is added to the etching gas.
It is suitable for performing gate electrode processing without addition. one
On the other hand, as shown in FIG.
When lowered to a low level, the plasma almost
It will be surrounded by the side wall. However, alumina ceramic
Is almost O due to ion sputtering.^*Release
do not do. Therefore, this state is due to the etching of the SiOx film.
Suitable for Of course, the elevating side wall protection ring 14
Is set to an intermediate level, an intermediate amount of O^*
Is supplied, and this is fine-tuned for etching conditions.
It can be used for adjustment. In the above example, the side wall of the chamber 1
Is an alumina-based ceramic, and an elevating sidewall protective ring is synthesized.
Although it was made of quartz, this constituent material was reversed,
Chamber sidewall made of synthetic quartz and alumina ceramics?
It may be combined with an elevating type side wall protection ring.
In this case, set the elevating side wall protection ring 14 to the highest level.
Raised state is suitable for etching SiOx film
The state where it is lowered to the lowest level is suitable for gate processing
State. Prior example 2 In this example, alumina-based ceramics (without releasing oxygen)
Inner wall of ring made of synthetic quartz with protective cover made of
For the outer ring and the protective cover
Alumina-based ceramic inner ring with a sliding window
Is a movable member in the chamber 1
See FIG. 3 and FIG. 4 for the ode type plasma device.
I will explain while. In addition, these inner and outer rings
It is generically referred to as a rotating side wall protection ring. FIG. 3 shows this triode type plasma apparatus.
From the rotary side wall protection ring
It is. The outer ring 20 has a circumferential surface on its inner wall surface.
Rectangular protection in every other 12 areas
The cover 21 is provided. So this means that oxygen
The first member that does not emit (a protection module made of alumina ceramics)
Bar) and a member that releases oxygen (wall material made of synthetic quartz)
However, it is apparently arranged alternately in the circumferential direction. one
Similarly, the inner ring 22 has a 12
Every other one has a rectangular window 23 at a total of six locations.
The relative position between the protective cover 21 and the window 23 is indicated by an arrow.
Can be changed based on the rotation of the ring in the C direction
This rotation can be performed by either the outer ring 20 or the inner ring 22.
Singly or with both rings at the same time
good. FIG. 4 is a sectional view taken along line XX of FIG.
The positional relationship between the protective cover 21 and the window 23 is shown for easy understanding.
It was done. FIG. 4A shows that the protective cover 21 is a window.
23, that is, completely exposed
When all of the contact surfaces are made of alumina ceramics
is there. In this state, the equipment originated in the etching reaction system
O^*Is not supplied. On the other hand, FIG.
21 is completely shielded by the inner ring 22, ie,
Quartz, the wall material of the outer ring, is exposed through window 23
This is the case. In this state, the exposed part of this quartz
Oxygen is sputtered in the etching reaction system^*But
Supplied. Note that O^*4 (a) and FIG.
Arbitrary setting by selecting an intermediate rotation angle in (b)
Of course you can. Using the rotating side wall protection ring as described above,
In this case, the structure of the chamber 1 located further outside these
The constituent material is not particularly limited. Also the outer phosphorus
Directly on the side wall of chamber 1 instead of using
A configuration in which a protective cover is provided may be employed. This and
The quartz chamber contains alumina ceramics.
Protective cover, quartz for alumina ceramic chamber
A protective cover will be provided. Prior example 3 In this precedent example, the triode-type plasma
Offset SiOx film pattern using
Dry etching of W-polycide film using
went. See FIGS. 5 and 6 for this process
I will explain while. FIG. 5 shows a sample wafer before etching.
And a gate SiOx film 22 on a Si substrate 21.
A W-polycide film 25 is formed through
Formed with an offset SiOx film pattern 26
is there. The W-polycide film 25 is composed of n
⁺Type polysilicon film (polySi) 23 and tongues
Ten silicide (WSix) film 24
It is. Here, the polysilicon film 23 is made of SiH₄
/ PH₃About 100 nm by thermal CVD using mixed gas
And the WSix film 24 is made of WF₆/ SiH₄
About 100 nm by thermal CVD using a mixed gas of He / He
Each is formed to a thickness. In addition, the offset
The SiOx film pattern 26 is formed by resist patterning.
And dry etching.
The distant pattern has already been removed by ashing.
You. Here, as an example, the following conditions HBr flow rate 50SCCM Cl₂Flow rate 50 SCCM Pressure 0.4Pa RF source power 800-1200W (13.56
MHz) RF bias power 10-100W (100-50
0 kHz) Wafer temperature Room temperature to 80 ° C Exposure area of lifting side protection ring 50-50% Then, the W-polycide film 25 was etched. Under the above conditions, an oxygen-based gas is added to the gas system.
Although it is not added, it is made of synthetic quartz
Oxygen-based chemical species are sputtered out of the protective ring 14.
As a result, the O^*Maintain the proper amount
I was able to. As a result, as shown in FIG.
Forming a gate electrode 25a having a favorable anisotropic shape
I was able to. Next, a specific embodiment of the present invention will be described.
You. Embodiment 1 In the present embodiment, the triode type plasma
Bit line of ASIC DRAM using switching device
SiOx / po to open contact holes
Continuous and consistent etching of the lySi / SiOx film stack
went. See FIGS. 7 and 8 for this process
I will explain while. FIG. 7 shows a sample wafer before etching.
And a fourth layer having a thickness of about 100 nm on the Si substrate 31.
1 SiOx interlayer insulating film 32, poly 100 nm thick
Silicon (polySi) film 33 having a thickness of about 500 nm
The second SiOx interlayer insulating film 34 is sequentially formed by, for example, LPCV
A film is formed by the method D, and further, for example, a chemical
A resist pattern 35 made of a width-based resist material is formed.
It was made. This resist pattern contains
For example, go through KrF excimer laser lithography
As a result, an opening 36 having a diameter of 0.25 μm is formed.
You. The polysilicon film 33 is used for this device.
This is the third polysilicon film in the
Is what it does. Next, this wafer is connected to the triode type
The second SiOx is set in the plasma etching apparatus.
Step 1 of etching interlayer insulating film 34, polysilicon
Step 2 of etching the silicon film 33, first SiO
Step 3 of etching the x interlayer insulating film 32
Ching was performed continuously. Steps 1 and 3
The switching conditions are common, for example, [Steps 1 and 3] CHF₃Flow rate 50 SCCM Ar flow rate 50 SCCM Pressure 0.67 ~ 133Pa RF source power 200-2000W (13.56
MHz) RF bias power 500W (100-500kHz)
z) Wafer temperature 25 ℃ 0% of the exposed area of the side-wall protection ring
Descends at And On the other hand, the etching conditions in Step 2 are as follows.
For example, [Step 2] HBr flow rate 0-50SCCM Cl₂  10-100 SCCM Pressure 0.27 ~ 1.3Pa RF source power 800-1200W (13.56
MHz) RF bias power 15W (100 ~ 500kHz
z) Wafer temperature 70 ℃ 100% of the exposed area of the lifting side wall protection ring (maximum level
Up to And By this etching, as shown in FIG.
Good anisotropy for laminated films with different etching characteristics
It is possible to open a contact hole 37 having a shape.
did it. This contact hole 37 has a
And the bit lines are embedded. Conventionally, this kind of laminated film is etched.
In some cases, SiOx
The etching of the film and the etching of the polySi film are
Must be performed by the
The risk of reduced throughput or new contamination?
Was. However, according to the present invention, as described above,
Changing the wall material of the chamber only by mechanical raising and lowering of the protection ring
Wafer can be transported during etching
There is no need to perform this operation, and the conventional problem does not occur. Although the embodiments have been described above, the present invention
Is not limited to these examples. for example
For example, the configuration of the triode etching system,
Details such as wafer configuration and dry etching conditions
It can be changed and selected. [0054] As is clear from the above description, the present invention
According to Ming, O^*Control of supply volume and internal constituent materials
Of restrictions on the etching target due to the difference in
Excellent anisotropic shape in dry etching, optimal
A high SiOx film selectivity can be achieved. Only
Also, one unit for dry etching where the optimum conditions differ greatly
Because it is possible to respond with a plasma device,
Improvements in put and particle levels are expected. Ma
In addition, it is conventionally complicated because it requires etching of different materials.
What can be simplified is the device structure
This will also increase the degree of freedom in design. Therefore the book
The invention is based on the realization of precise and efficient dry etching
It is important for miniaturization, high integration, and high performance of semiconductor devices.
It is a contributor.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view showing a configuration example of a triode type plasma etching apparatus to which the present invention is applied;
(A) is a state in which the elevating type side wall protection ring is raised,
(B) respectively shows the lowered state. FIG. 2 is a perspective view showing a part of a chamber and a liftable sidewall protection ring of FIG. 1; FIG. 3 is a perspective view showing a rotary side wall protection ring as a modification of FIG. 2; 4A and 4B are cross-sectional views taken along the line XX of FIG. 2, wherein FIG. 4A shows a state in which an inner ring shields a wall material of an outer ring, and FIG. . FIG. 5 is a schematic cross-sectional view showing a state in which a SiOx film pattern is formed on a W-polycide film in a process example to which the dry etching method of the present invention is applied. FIG. 6 is a graph showing the relationship between the SiOx film pattern shown in FIG.
FIG. 3 is a schematic cross-sectional view showing a state in which a polycide film has been anisotropically etched. FIG. 7 is a schematic cross-sectional view showing a state where resist patterning has been performed on a SiOx / polySi / SiOx laminated film in another process example to which dry etching of the present invention is applied. FIG. 8 is a view showing a state in which Si is formed using the resist pattern of FIG. 7 as a mask;
FIG. 4 is a schematic cross-sectional view showing a state in which an Ox / polySi / SiOx laminated film is continuously and continuously etched. FIG. 9 is a schematic cross-sectional view showing a configuration example of a conventional general triode type plasma etching apparatus. [Description of Signs] 1 chamber, 2 upper ground electrode, 5 side wall electrode,
7 Wafer stage, 10 RF for plasma excitation
Power supply, 12 RF power supply for bias application, 14 lifting / lowering side wall protection ring, 15 support member, 16 actuator, 20 outer ring, 21 protection cover, 2
2 inner ring, 23 window, 25 W-polycide film, 25 a gate electrode, 26 offset Si
Ox film pattern, 32 first SiOx interlayer insulating film,
33 polysilicon film, 34 second SiOx interlayer insulating film, 35 resist pattern, 37 contact hole, P plasma, W wafer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 21/3065 C23F 4/00 H05H 1/46

Claims (1)

(57) Claims 1. Excited by an electric field applied between an upper electrode constituting a ceiling portion of a chamber and a side wall electrode provided along at least a part of a side wall of the chamber. A dry etching method for performing predetermined etching on a substrate housed in the chamber by using a plasma to be etched, wherein the etching does not release an oxygen-based chemical species even when the substrate is in contact with the plasma. And a second member that releases an oxygen-based chemical species upon contact with the plasma, wherein the relative ratio of the respective plasma contact areas of the first member and the second member is controlled using control means. A step of etching the insulating film by reducing the relative ratio of the plasma contact area of the second member, and a step of etching the wiring film by increasing the relative ratio. It allows a dry etching method for performing continuous consistent etching of a laminated film made of an insulating film and wiring film for.